Answer:
Deleting the Segment option is not yet available to the user/administrator.
As of now, the available option is to Edit the information for each of them.
For Tags, you have to click the tag and it will show you the trash bin icon.
If the user/administrator wants to delete any a segment, you must contact our support team by sending an email to support@tryletterhead.com or by logging a ticket via the Help Center. Please provide the following details upon your request:
1. Channel's name
2. Segment name. (that you would like to be deleted)
You may click this Sengments and Tags for more details.